1. Field of the Invention
The present invention relates to a washing machine, and more particularly, to a washing machine having an improved circulation apparatus for pumping water in a lower side of the tub and discharging the pumped water from an upper side of the tub.
2. Discussion of the Related Art
In general, a washing machine is an apparatus for eliminating contaminants from laundry by the interaction of detergent and water.
Washing machines are generally classified into agitator type, pulsator type, and drum type washing machines.
The agitator type washing machine washes laundry by rotating a washing rod overtopping at the center of the washing tub in left and right directions. The pulsator type washing machine washes laundry using the frictional force generated between water current and laundry by rotating the disk-shaped pulsator in right and left directions. The drum type washing machine washes laundry by loading water, detergent and laundry into a drum with a plurality of protruded tumbling ribs installed in an inner surface of the drum and rotating the drum at a low speed.
In recent years, in order to enhance the washing efficiency of the agitator type, pulsator type and drum type washing machines, a variety of auxiliary units are additively provided, such as a washing water circulation apparatus, for example. The washing water circulation apparatus allows objects to be washed received in the drum or washing tub to be wet rapidly, and enhances the washing efficiency by increasing the frictional force due to water current.
The washing water circulation apparatus is configured to pump water in an inner lower space of the tub and discharge the pumped water from the upper side to the inner space of the drum or washing tub. The washing water circulation apparatus has a plurality of small injection holes for injecting the pumped water into the inner space of the drum or the washing tub.
However, the water in the tub contains a considerable amount of foreign particles such as lint. Therefore, the foreign particles are pumped along with the water in the tub through the washing water circulation apparatus and then injected through the injection holes. Over a long period of time, the injection holes are choked with the foreign particles, causing problems in the washing machine.
In addition, because the water that is pumped through the washing water circulation apparatus is generally injected only in one direction, the pumped water cannot be uniformly injected into the washing objects received in the drum or washing tub.
Accordingly, all the washing objects cannot be rapidly wet, making it difficult to obtain high washing efficiency.